Importing Sisyphus within IPython fails

[albertz]

(I wanted to import actually sth from i6_experiments, but that imported sisyphus.)

...

File ~/setups/2025-08-aed-large/tools/sisyphus/sisyphus/__init__.py:4
      2 from .job import Job
      3 from .task import Task
----> 4 import sisyphus.toolkit as tk
      5 from sisyphus.loader import RecipeFinder
      7 # setup_path and gs will be removed in the future since they are both accessible via tk

File ~/setups/2025-08-aed-large/tools/sisyphus/sisyphus/toolkit.py:56
     54 import sisyphus.block
     55 from sisyphus.block import block, sub_block, set_root_block
---> 56 from sisyphus.async_workflow import async_run, async_gather, async_context
     57 from sisyphus.delayed_ops import Delayed
     58 from sisyphus import cleaner

File ~/setups/2025-08-aed-large/tools/sisyphus/sisyphus/async_workflow.py:2
      1 from sisyphus import graph
----> 2 from sisyphus.loader import config_manager
      3 from sisyphus.tools import extract_paths
      4 from typing import Any

File ~/setups/2025-08-aed-large/tools/sisyphus/sisyphus/loader.py:260
    255     @classmethod
    256     def invalidate_caches(cls):
    257         PathFinder.invalidate_caches()
--> 260 config_manager = ConfigManager()

File ~/setups/2025-08-aed-large/tools/sisyphus/sisyphus/loader.py:18, in ConfigManager.__init__(self)
     16 self._config_readers = []
     17 self._waiting_reader = {}
---> 18 self.loop = asyncio.get_event_loop()
     19 self._reader_threads = defaultdict(dict)
     20 self._current_config = None

File /usr/lib64/python3.12/asyncio/events.py:702, in BaseDefaultEventLoopPolicy.get_event_loop(self)
    699     self.set_event_loop(self.new_event_loop())
    701 if self._local._loop is None:
--> 702     raise RuntimeError('There is no current event loop in thread %r.'
    703                        % threading.current_thread().name)
    705 return self._local._loop

RuntimeError: There is no current event loop in thread 'MainThread'.

I think importing should always work, no matter the environment.

This is with Python 3.12.9 and IPython 9.6.0.

[albertz]

I did some quick search for this error. But it's not really clear.

E.g.: ipython/ipython#14643 But this seems fixed/outdated, or only relevant for Python 3.9, and older IPython 8?

Maybe related:
vibrantlabsai/ragas#1136
pytest-dev/pytest-asyncio#658

[albertz]

Note, Gemini was helpful for a suggestion on a workaround:

pip install nest_asyncio

And then in IPython:

import nest_asyncio
nest_asyncio.apply()

import sisyphus
# Or import i6_experiments

And that works.

[michelwi]

And that works.

So do we still need to take action here? E.g. if the problem is related to nesting async calls, we could try to import from async_workflow only if it is actually needed

[albertz]

So do we still need to take action here?

I think it should be possible to import sisyphus within IPython (and maybe other places which would have similar conditions as IPython) without such a workaround.

I'm not sure on the best solution though. Maybe all that access to asyncio should be done lazily, only when really needed?